Keep track of the moon, if there's no sky where you live. To keep track of the moon and the stars, HomePlanet is pretty complete (7.2 megs); and OpenUniverse (4.5M, open source) is pretty nifty.
see also:MoonPhase (357K, shareware)

Replacement (almost) for Windows Explorer; includes a toolbar for your favorite programs, lets you view files from within PowerDesk (if you have QuickView installed), keep a history list of your favorite folders; many more handy features. (OnTrack's ad is very unobtrusive.)

Audio playback, encode (multiple) audio files; very tightly-integrated controls; efficient good looks and sounds great! (cnet) Written by a considerate programmer who doesn't muck around with your registry. Also available is an optional file-association program (SmxExt01.exe associates .mp3 and .m3u with SCMPX, although this can interfere with streaming mp3).Also:Simple, nice player/ripper (1.1M, freeware, works on Win2K, [spyware?])FreeAMP (Open Source, 2.1M)

Free-form hierarchical (tree) program for managing your text . Quite good as a Personal Information Manager (PIM), will even run off a floppy (without the documentation/install files, the program is only 233K).
See also:
Keynote (freeware)

Compress & decompress (e.g. zip & unzip) a large variety of file formats. Nearly all downloadable programs on the internet require some kind of decompression program like WinZip. Check out compatible freeware programs on ZDNet, or get PowerDesk (adware) or 7 Zip (open source).